And so my Hawk 250 experience begins.

[Megadan]

Originally Posted by Border411

Do the MCO's for the Hawk state "Motorcycle" or "Dirt bike"????

MCO Stated Motorcycle, but when you submit the request on their website, in the notes on the form I also put in "Please make sure MCO states "Motorcycle" as the vehicle type." Just to be safe.

Originally Posted by Sochin

Dan, I also adjusted the valves before 1st start of the engine (which had no clearance whatsoever), I set them to 0.004 for intake and exhaust for brakein. It was a little noisy at 1st, but it quieted down after 2nd oilchange and 30 some miles......so I'll keep an eye on it.

I will definitely look into the jet sizes you mentioned and buy 2-3 extras just because. I REALLY like this little bike. Uni filter coming, and I have a feeling a full exhaust will be in place shortly even tho I like the soundlevel of the stock exhaust as mine will be used for hunting too.

I adjusted mine before the first start too. The real difference was, mine never really changed noise level. I gather from your previous reply that your first run was with the oil that came in the bike, then you changed it over to Rotella. That is the reason why your valves likely got quieter. The oil that comes in these things is total garbage, and I don't entirely think it's motor oil lol.

The exhaust makes a huge difference, so it is worth doing, but I can understand your wanting to keep it quieter. The standard ebay exhaust is a bit louder obviously, but there is always the option to run a slightly more expensive FMF or Pro Circuit exhaust system, or swap out the muffler that comes with the Ebay system for something that has a removable silencer. The other option would be to at least gut the cat from the stock exhaust, and at least clean up the weld on the inlet side of the header pipe.

[Sochin]

I changed out the factory storage oil with Rotella 15W40 before 1st start, let it warm up and ran it slowly up and down carefully in throttle for 6 miles. Then changed it again with 2nd batch of Rotella 15W40.

Yeah, I will run it a little bit more before I decide upon complete exhaust work or not. I need to replace the chain and sprockets in the next two days. I just didn't have it in me after setting up the bike and locktiting everything to replace them quite yet. I spent a good 10 hours all together assembling things before 1st start.

[Megadan]

Originally Posted by Sochin

I changed out the factory storage oil with Rotella 15W40 before 1st start, let it warm up and ran it slowly up and down carefully in throttle for 6 miles. Then changed it again with 2nd batch of Rotella 15W40.

Yeah, I will run it a little bit more before I decide upon complete exhaust work or not. I need to replace the chain and sprockets in the next two days. I just didn't have it in me after setting up the bike and locktiting everything to replace them quite yet. I spent a good 10 hours all together assembling things before 1st start.

Gotcha. Just make sure to keep an eye on those valve clearances during the first few hundred miles. They will likely shrink a bit and need re-adjusting one or two times. I just took the extra few minutes to check it at each oil change.

Taking that extra time to assemble it is worth it, but I can also understand not wanting to go back after doing it lol. I was the same way. After taking my bike apart a few times I am just about done with having to do so over and over again, but my OCD meticulous nature won't leave "good enough" alone, so I keep going back and working on it.

[Sochin]

I ordered a 22.5 and a 25 pilot jet and a 102.5 and a 105 main jet based upon your advice. I runs fine except for a slight stumble at takeoff/low throttle. I now I will have some jet range and needle settings to play with to hone it in. I'm using this opportunity to learn more about carburation and air/fuel mixtures. I'm normally and FI guy. Thanks again, Dan.

[Megadan]

While it's not an exact science, those jets should get you close. I always suggest starting with the richer of the jets. 25 pilot and 105 main, set the needle clip in the middle.

I am pretty confident the 25 pilot should work perfectly for you, but I always recommend having other sizes, because climate and other factors, even individual engines, can vary slightly.

The 105 main jet on the other hand may be a touch rich since it works well for people at sea level, which is why I suggested the 102.5. A plug chop will reveal where that sits.

Don't be afraid to ask any tuning questions on here. There are a few members on here that have a lot of experience with carb tuning besides me that can help guide and troubleshoot.

The only real thing to remember with these carbs is that, while each jet and setting mainly affects a given throttle position, I.E. The pilot jet primarily affects idle to 1/4 throttle, it still adds a tiny bit of fuel to both the needle range (1/4 to 3/4) and Main (3/4 to wide open). While half steps (22.5 to 25) usually won't affect the others enough to make a notable difference, a full step (25 to 30) can sometimes require tweaking of one of the other settings/sizes.

[Sochin]

Great, now my gas tank is leaking in the seam close to the rear of it. Well, it is within 90 warranty so here it goes I suppose?

[Megadan]

Originally Posted by Sochin

Great, now my gas tank is leaking in the seam close to the rear of it. Well, it is within 90 warranty so here it goes I suppose?

If you can get it fixed under warranty, definitely go that route. Why shell out money you don't have to?

[Sochin]

I got some JB Weld Stilstik putty and smoooshed in on there. I'm gonna give it 24 hours before I assemble and see if it works.

[green_hawk250]

Originally Posted by Sochin

Great, now my gas tank is leaking

I found this potential problem with my Hawk as well. Here is my solution from the previous post:
------------------
Additional vibration/noise isolation has been added to the tank area.
At the place shown on the following picture the tank was simply laying on the frame touching it with its welded joint, because the original rubber mount is too thin. There is a good chance that the welding on the tank would be damaged within the time due to the rubbing vibration of the metal to metal at the touch point. That could cause a gas leak, not to mention that the tank body works as a noise acoustic resonator. It was fixed by installing 1/4 inch thick rubber insertion as shown.





Some other tips to reduce vibration noise from the tank.

Rubber tube inserts on both sides:



Cover bracket installation changed.




Eliminating annoying vibration sound coming from gas tank when it close to reserve. Turns out, the source of the sound is the key hole cover. The fix is easy. Just make felt insert as shown. Make sure it is slightly smaller than the cower, so the cover's lip will hold it inside. The rubber wouldn't work. Because of higher friction, it would fall out every time you open the cover.

[emptypockets]

Good to know about the gas tank issue! I'll get some more padding in there before it goes.

[Sochin]

Here is a picture of the leak close to the petcock area.